Get a list of databases

Hi! I have a short question...

On the attached picture I can see a DataLink dialog
that allows me to choose a database source from
a specified SQL server.

I've written a program that also connects successfully
to a SQL server but I don't know how to get a list of
available databases.

When my application starts, the 'Initial Catalog' parameter
is set to null and so it connects to the first database
entry (in this case 'master').

Any ideas how to get a list of databases from the specified
SQL server?

thx!